Now with support for blend equations (and fixed some other stuff)

In GameMaker 2024.4 we gained access to blending equations in addition to blend mode constants. We can now play with these in the editor, too.

I also fixed a bunch of annoying things about the old program:

• Program is now 64-bit
• Fixed the “multiply” blend mode preset
• Adding a layer will insert the layer above the currently selected one instead of below it
• Dragging images into the window will always add them as new layers
• Rearranged UI elements to make them a bit less weird and awkward
• Dark mode